From: Razvan Cojocaru <rzvncj@gmail.com>
To: Andres Lagar-Cavilla <andreslc@gridcentric.ca>
Cc: Tim Deegan <tim@xen.org>,
"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>
Subject: Re: [PATCH V2] mem_event: Allow emulating an instruction that caused a page fault
Date: Tue, 22 Jan 2013 16:22:16 +0200 [thread overview]
Message-ID: <50FEA098.6030105@gmail.com> (raw)
In-Reply-To: <7A228E53-E6F8-4C1A-8BAF-F7558600FB5B@gridcentric.ca>
> Razvan, have you tried the n2rwx mode? It'll cause an event for the first access to each page. It'll automatically patch the access (hence 2 rwx) to allow execution to continue unhindered.
>
> So user-space doesn't decide anything, but gets informed about everything (within the constraints of mem event, i.e. no foreign mappings, no Xen mappings).
Hello, yes, I did look at that. Unfortunately, my userspace application
needs to be notified about subsequent writes to the same page, and once
the page goes to rwx mode there are no further events. So that's not a
very useful mechanism.
> If you want to know about every write and decide on every write… you can't have your cake and eat it too, right?
Right.
Thanks,
Razvan Cojocaru
next prev parent reply other threads:[~2013-01-22 14:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <mailman.21624.1358431706.1399.xen-devel@lists.xen.org>
2013-01-17 15:38 ` [PATCH V2] mem_event: Allow emulating an instruction that caused a page fault Andres Lagar-Cavilla
2013-01-17 15:50 ` Razvan Cojocaru
2013-01-21 23:13 ` Razvan Cojocaru
2013-01-22 12:31 ` Tim Deegan
2013-01-22 12:53 ` Razvan Cojocaru
2013-01-22 13:20 ` Tim Deegan
2013-01-22 13:47 ` Razvan Cojocaru
2013-01-22 14:02 ` Andres Lagar-Cavilla
2013-01-22 14:22 ` Razvan Cojocaru [this message]
2013-01-22 14:26 ` Tim Deegan
2013-01-22 14:45 ` Razvan Cojocaru
2013-01-24 11:05 ` Tim Deegan
2013-01-24 11:34 ` Razvan Cojocaru
2013-01-17 14:02 Razvan Cojocaru
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